CHEM 211 Study Guide - Quiz Guide: Solubility Equilibrium
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Chemistry 211 2014 homework assignment # 2 - volumetric analysis and. Complexometric titrations due thursday october 9th at 8 am: the problem links two equilibria, the solubility equilibrium for a weakly soluble salt (caf2 ) and the ph equilibrium for a weak, monoprotic acid (hf). Derive an expression for the solubility of caf2 as a function of h+ concentration. Plot the concentration of ca2+ (which is the solubility of caf2 ), f-, and h+ in water as a function of ph from ph 1 to 12. Excel or similar spreadsheet to do the calculations and the plot. Ka for hf = 6. 8 x 10 -4. We want an expression relating [f-] in terms of [h+]. The solubility of caf2 is the number of moles/l of caf2 dissolved and is equal to 1/2 [f-] because : So, we want to find an expression relating [f-] in terms of [h+] Caf2 ca2+ + 2f- ksp = 3. 9 *10-11.
